1. Field of the Invention
The present invention relates to an image forming apparatus such as a laser printer and a developer cartridge to be removably provided in the image forming apparatus.
2. Description of the Related Art
In an image forming apparatus such as a laser printer, the developer cartridge that is removably mounted in an apparatus body has a toner accommodation chamber that accommodates a toner, a developer roller which carries the toner, a supply roller for supplying the toner accommodated in the toner accommodation chamber to the developing roller, an agitator for agitating the toner accommodated in the toner accommodation chamber, and the like.
In such developer cartridge, a gear mechanism section for rotationally driving an agitator, a developer roller and a supply roller is provided (e.g. c.f. Japanese Unexamined Patent Publication No. 2003-295614).
The gear mechanism section comprises an input gear for receiving a driving force transmitted from the apparatus body, a developer roller driving gear for rotationally driving the developer roller, a supply roller driving gear for driving the supply roller, and an agitator driving gear for driving the agitator. The gear mechanism section receives the driving force transmitted from the apparatus body at the input gear, and then the input gear transmits the force to the developer roller driving gear, the supply roller driving gear and the agitator driving gear.
In the apparatus body, a motor and a coupling member to which the driving force from the motor is transmitted are provided. The coupling member is retreatably connected with the input gear in synchronization to a cover member, which is opened/closed when a developer cartridge is attached/detached.
That is to say, when the cover member is opened, the coupling member retreats relative to the input gear, and when a cover member is closed, the coupling member advances relative to the input gear. Therefore, when a cover member is opened and a developer cartridge is mounted to the apparatus body, and then the cover member is closed, the coupling member advances relative to the input gear, whereby connecting the coupling member and the input gear.